Full Idea
I prefer to think of essence as a transworld heir line, rather than as the more familiar collection of properties, because the latter too much suggests the idea of a fixed and final essential description.
Clarification
The 'heir line' links counterparts, rather like relatives
Gist of Idea
Essence is a transworld heir line, rather than a collection of properties
Source
David Kaplan (Transworld Heir Lines [1967], p.100)
Book Reference
'The Possible and the Actual', ed/tr. Loux,Michael J. [Cornell 1979], p.100
A Reaction
He is sympathetic to the counterpart idea, and close to Lewis's view of essences, as the intersection of counterparts. I like his rebellion against fixed and final descriptions, but am a bit doubtful about his basic idea. Causation should be involved.